Most tooth whitening systems in use today contain peroxide or other bleaching material. Peroxide-based products may present formulation difficulties, due to the volatility and reactivity of hydrogen peroxide, and many countries strictly regulate peroxide levels in tooth whitening products.
There is also a need to protect the teeth from bacteria and plaque formation, and to provide sustained delivery of active agents, for example fluoride, antibacterial agents, and remineralization agents.
Polymer delivery systems for application to the teeth have in general not proved sufficiently durable to remain on the teeth for extended periods. The teeth are physically abraded by brushing and chewing and are moreover exposed to a wide range of temperatures and pH levels as a result of eating and drinking. Under ordinary conditions, therefore, most polymers will not remain on the teeth for very long. Moreover, it is desirable that the polymers themselves to not readily take up stain or otherwise discolor the teeth.
There is an unmet need in the art for a delivery system that can provide whitening particles and other active ingredients to the teeth and protect the teeth from plaque and biofilm formation for extended periods.